How Much Improvement With 320i

CHAZZ · 01-27-2002, 06:28 PM

Started work on my project car,thanks to the unseaonable warm
weather. When I took the front calipers off found all they need are a rebuilding & a good cleaning. What would I gain by going to 320i calipers since the most of my driving will be highway? Will
I have that much more stoping power?

Thanx
Chuck

Jeff Nelson · 01-28-2002, 05:07 PM

My stock brakes always stopped me but didn't give me much confidence. It took a lot of pedal pressure and didn't give me a warm feeling. After doing the upgrade it feels much better. I'm never left wondering if it will stop in time. It still requires a lot of pedal pressure but they work good.

If you do search on this forum for "320i" you'll find lot's of comments about this upgrade.

DSPTurtle · 01-28-2002, 05:43 PM

As everyone here knows, I am a HUGE fan of the 320i upgrade. However, I found out this weekend that because of that upgrade you will get bumped to D-Prepared in SCCA SoloII rules. This means you can change all kinds of stuff. I will make the sacrifice not to be competitive right now just ot know that my baby will stop when I ask her to!!! By the way, you should really do the 19mm Master Cylinder if you make that change, as well as get rid of the Prop valve.
JB

John Rogers · 01-28-2002, 09:31 PM

The larger calipers stop a little better but they really take away heat much better since we are restricted to the solid rotors all we can do to help is better. Also some cooling ducts will help to minimize brake fade. Either calipers will easily lock the wheels, but that is not what you want. Smooth, even, consistant and long lasting braking for a 20 minute race session with no fade is the goal. This will make everyday street driving that much safer. Good luck.

paulhagedorn · 01-28-2002, 11:24 PM

Maybe I am a little bit goofy in the head, but I think my stock brakes are pretty good. I have rebuilt ones all around, though. The rear brakes were frozen before I replaced them, so the brakes sucked then. Now, I feel as if I can stop pretty well. I do have the 19mm m/c, but as we know, that doesn't make the brakes better, just changes pressure needed to apply them.
I can lock the wheels easily by romping on the pedal.

Brant · 01-29-2002, 06:17 AM

I'm not going to answer your actual question, but .......

I've raced a few seasons on stock brakes..... There is no problem with the stock brakes.. My personal theory is that when people upgrade to the bmw calipers they are making big jumps in pad compound also and realistically most of the noticeable difference is coming in pad compound....

I run big brakes now too.... (aluminum S calipers) but I would first recommend to anyone that they set their rear venting, put good pads in, replace the master and proportioning valves, and run some good fluid like ATE blue...... With this set up I never cooked my stock brakes even with 2 drivers in 110 degree heat.......

brant

nhallman · 01-29-2002, 09:00 AM

I just rebuilt the front brakes on my 1.8 with all stock materials and it stops fine. If you're going to be doing mostly highway driving, I don't think you're going to lose much by sticking with the stock brakes - unless you plan on autocrossing, and even then I'd think twice if what JB says is true about getting bumped into D-Prepared.

larrym · larrym's Garage

makes a helluva difference! IF you also eliminate the prop valve & repalce it w/ vw TEE

try it & you'll never go back!

Joe Bob · Joe Bob's Garage

Do they add points for aggressive pads, cross drilling or slotting? If not, go that route....

BenI · 02:46 PM

Why do you replace the prop valve when going to 320i calipers? Good side, bad side to this move? I have 320 calipers up front and a 911 MC, but still got the prop valve...what am I missing out on?!?

larrym · larrym's Garage

the prop valve is the source of the spongy feel that so many 914's suffer (per Bruce Anderson, et al)

I did this bmw conversion on 3 914/4's, with 19mm master; with the bigger calipers the brakes work great w/o any prop valve, but i can vouch that if you remove the valve from a stock brake car, the front's will lock first (got one like that right now), in which case you need to put in an adjustable type like Summit's ( I have one of those on my sixer in lieu of the prop valve)

mike mueller · 01-30-2002, 03:20 PM

Keep the stock calipers and invest your money in good pads and an aftermarket P-valve........

replace the lines with new rubber or DOT stainless lines,
change the brake fluid (all of it) once a year,

do you have decent tires? if you have some Sears brand $35 tire, the biggest caliper or rotor is not going to help you.